A modern cab for a large truck or the like is normally provided with at least one bunk in a cab space behind the driver's seat. The bunk is meant to allow a second driver to sleep or rest, while a first driver is driving the truck, so that stops during a long journey can be kept at a minimum.
The bunks in use today can seldomly be adapted to a specific demand from the driver. However, there is an increasing demand for changing the width or the length of the bunk depending on the size of the driver, and also for choosing a certain bottom of the bunk to satisfy different persons' requirements of comfort.